The invention relates to a plant for removing fines from fiber fluff comprising a forming wire, a forming head which is placed above the forming wire and arranged for air-laying fiber fluff into a layer upon the forming wire, at least one channel for carrying, in a flow of air, fibers from a supply of fibers into the forming head, a suction box placed at the lower side of the forming wire, at least one vacuum fan connected to the suction box for generating an air flow from the forming head, through the fluff, the forming wire, and the suction box to the at least one vacuum fan.
Fluff of e.g. cellulose fibers and/or synthetic fibers is generally used for producing air-laid webs in plants where the fluff is air-laid in layers upon at least one wire, and the air-laid layers subsequently run through a number of further production steps for obtaining a wanted structure and quality of the web.
Such webs are among other things used for the manufacturing of disposable non-woven products of which can be mentioned,
absorbent core material for feminine hygiene articles,
incontinence articles,
diapers,
table top napkins,
hospital products such as bed protection sheets,
wipes, and
towels.
The webs used for such products usually have a weight of about 20-80 g/m2.
Heavy-duty webs having weights of about 80-2000 g/m2 can advantageously be used for producing e.g. corrugated board and heat—and/or sound insulating materials.
The fiber fluff normally contains fines which are small fiber particles in order of 10 to 50μ. These fines tend to reduce the quality of the air-laid web and with that also the products which are manufactured of the web.
The above named further production steps of the fluff frequently also include a hydroentangling process where jets of water are, under influence of a pressure of e.g. 100 bar, directed through fine nozzles towards the fluff, thereby entangling the fluff into a coherent web.
The water used for hydroentangling the fluff is normally recirculated back to the nozzles for being reused whereby fines in the fluff will be dispersed in the water penetrating the fluff.
The dispersed fines in the reused water tend to get stuck in the fine nozzles which then stop to function thereby causing a costly stop-down for the total plant.
In the recirculation cycle is therefore inserted a filter for removing fines from the water.
Filtering particles as small as fines require, however, a complex filter having a number of filtering steps. The filter in itself and the servicing of the filter are therefore very costly.
The disadvantages of the prior art are now resolved by the present invention.